Traveling vehicle

ABSTRACT

A traveling vehicle includes a vehicle body, a left swing part, a right swing part, and an interlocking link mechanism. The left swing part and the right swing part are supported on the vehicle body so as to be swingable in the up-down direction, respectively. A left support part supporting a left front wheel is provided on a front part of the left swing part so as to be rotatable about a left steering shaft. A right support part supporting a right front wheel is provided at a front part of the right swing part so as to be rotatable about a right steering shaft. The interlocking link mechanism rotates one of the left support part and the right support part in conjunction with the other. The interlocking link mechanism is provided between the left support part and the right support part.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119 toJapanese Patent Application Serial No. 2019-140137 filed on Jul. 30,2019. The contents of this application are incorporated herein byreference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a traveling vehicle.

Discussion of the Background

A traveling vehicle including a pair of front wheels in left and righthas been conventionally known. Japanese Patent No. 6210852 discloses asaddle type vehicle that is a traveling vehicle of this type.

In the saddle type vehicle disclosed in Japanese Patent No. 6210852, ahandle stem is fixed to distal end of each front wheel axle of the leftand right front wheels. The handle stem extends upward so as to inclineobliquely rearward from the distal end of the front wheel axle. A handlegrip is provided on an upper portion of the handle stem. Further, thissaddle type vehicle is provided with a steering mechanism including acylinder mechanism as a steering device. The steering mechanism is usedto adjust the steering angles of the left and right wheels.

In the configuration of Japanese Patent No. 6210852 described above, itis necessary to individually switch the steering angles of the left andright front wheels on both the left and right sides of the saddle typevehicle. Thus, there is room for improvement in terms of improving theoperability for steering the traveling vehicle.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a traveling vehiclewith the following configuration is provided. That is, the travelingvehicle includes a vehicle body, a left swing part, a right swing part,a left support part, a left front wheel, a right support part, a rightfront wheel, and an interlocking link mechanism. The left swing part isarranged on one side in a vehicle width direction, is provided so as toextend forward from the vehicle body, and is supported on the vehiclebody so as to be swingable in an up-down direction. The right swing partis arranged on the other side in the vehicle width direction, isprovided so as to extend forward from the vehicle body, and is supportedon the vehicle body so as to be swingable in the up-down direction. Theleft support part is provided on a front part of the left swing part soas to be rotatable about a left steering shaft. The left front wheel isrotatably supported by the left support part and is configured to changean orientation of the left front wheel by rotation of the left supportpart about the left steering shaft. The right support part is providedat a front part of the right swing part so as to be rotatable about aright steering shaft. The right front wheel is rotatably supported bythe right support part and is configured to change an orientation of theright front wheel by rotation of the right support part about the rightsteering shaft. The interlocking link mechanism is configured to rotateone of the left support part and the right support part in conjunctionwith the other when the other of the left support part and the rightsupport part rotates. The interlocking link mechanism is providedbetween the left support part and the right support part.

Thus, in the traveling vehicle including the left front wheel and theright front wheel, it is possible to realize that the vehicle bodyleans. Further, based on the rotation of one of the left support partand the right support part, the rotation state of the other of the leftsupport part and right support part can be changed That is, based on thesteering angle of one of the left front wheel and the right front wheelcorresponding to the one of the left support part and the right supportpart, the steering angle of the other of the left front wheel and theright front wheel corresponding to the other of the left support partand the right support part can be changed. Therefore, it is possible torealize good operability in steering the traveling vehicle.

As a result, the steering operability can be improved for a travelingvehicle including left front wheels and right front wheels.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings, wherein:

FIG. 1 is a side view of a traveling vehicle according to an embodimentof the present invention;

FIG. 2 is a front perspective view showing the configuration of thefront of the traveling vehicle;

FIG. 3 is a side view showing the configuration of the front of thetraveling vehicle;

FIG. 4 is a front view showing the configuration of the front of thetraveling vehicle;

FIG. 5 is a front view showing a non-lean state of a vehicle body;

FIG. 6 is a front perspective view showing a state in which the left andright front wheels are turned for steering from neutral state to theleft in FIG. 2; and

FIG. 7 is a view showing a lean state of the vehicle body.

DESCRIPTION OF THE EMBODIMENTS

The embodiments will now be described with reference to the accompanyingdrawings, wherein like reference numerals designate corresponding oridentical elements throughout the various drawings. Firstly, a travelingvehicle 1 of this embodiment will be generally described with referenceto FIG. 1. FIG. 1 is a side view of the traveling vehicle 1 according tothis embodiment.

The traveling vehicle 1 shown in FIG. 1 includes a vehicle body 3, afront wheel 4, and a rear wheel 5. The traveling vehicle 1 is a saddletype vehicle in this embodiment. A driver rides on the traveling vehicle1 while straddling the vehicle body 3 to drive the traveling vehicle 1.It is noted that the type of traveling vehicle is not limited to thesaddle type vehicle.

In the following description, front, rear, left, right, up, and downmean front, rear, left, right, up, and down as seen from the driver whorides on the traveling vehicle 1, respectively, unless otherwisespecified. A left-right direction corresponds to a vehicle widthdirection of the traveling vehicle 1.

Two front wheels 4 are arranged in pairs in left and right relative tothe vehicle body 3, and is provided at a front part of the travelingvehicle 1. The left and right front wheels 4 are arranged atpredetermined intervals in the left-right direction. One rear wheel 5 isprovided at a center of the vehicle body 3 in the left-right direction,and is arranged at a rear part of the traveling vehicle 1.

The vehicle body 3 supports a drive source for driving the travelingvehicle 1. In this embodiment, an engine 8 shown in FIG. 1 is used asthe drive source. The engine 8 functions as a power unit for driving therear wheel 5 that is a driving wheel, and is configured as a gasolineengine, for example. A driving force generated in the engine 8 isshifted by a transmission gear (not shown) and transmitted to the rearwheel 5 via a drive chain 9. It is noted that, instead of the engine 8,an electric motor may be used as the drive source of the travelingvehicle 1, for example.

The vehicle body 3 includes a vehicle body frame 11. The vehicle bodyframe 11 is a strength component serving as a framework for supportingthe engine 8, etc., and is formed by using a metal pipe, for example.Left and right front wheel arms 12 and a rear wheel arm 13 are attachedto the vehicle body frame 11. The left and right front wheels 4 arerotatably supported by the left and right front wheel arms 12,respectively. The rear wheel 5 is rotatably supported by the rear wheelarm 13.

A seat 15 on which the driver sits is provided in an upper part of thevehicle body 3. A steering handle 17 operable by the driver sitting onthe seat 15 is arranged forward of the seat 15. The steering handle 17is connected to the front wheels 4. The vehicle body 3 is coupled withthe front wheels 4 via a suspension device 20.

Next, a configuration of the left and right front wheels 4 and thesteering handle 17 will be described with reference to FIGS. 2 to 5.FIG. 2 is a front perspective view showing a configuration of the frontpart of the traveling vehicle 1. FIG. 3 is a side view showing theconfiguration of the front part of the traveling vehicle 1. FIG. 4 is afront view showing the configuration of the front part of the travelingvehicle 1. FIG. 5 is a front view showing a non-lean state of thevehicle body 3.

In the following description, as for the left and right front wheels 4,the left wheel may be referred to as “left front wheel 4L” and the rightwheel may be referred to as “right front wheel 4R”. As for the left andright front wheel arms 12, the left arm may be referred to as “leftfront wheel arm (left swing part) 12L” and the right arm may be referredto as “right front wheel arm (right swing part) 12R”.

The steering handle 17 is a type of handle that can be separated in leftand right, and the separated parts are connected to the left and rightfront wheels 4, respectively. A configuration for supporting the leftand right front wheels 4 and a configuration for connecting the steeringhandle 17 and each of the left and right front wheels 4 aresubstantially bilaterally symmetric. Therefore, a configuration on theright side of these configurations will be mainly described below.

The right front wheel arm 12R is arranged on a right side, which is oneside in the vehicle width direction. The right front wheel arm 12R isprovided to extend forward from the vehicle body 3, and is supported bythe vehicle body 3 so as to be able to swing in an up-down direction.The right front wheel arm 12R is spaced from the left front wheel arm12L in the left-right direction so as to be form a predetermined gap.The right front wheel arm 12R is positioned inside in the vehicle widthdirection compared to the outer surface in the vehicle width directionof the right front wheel 4R.

A base end (rear end) of the right front wheel arm 12R is supported by afront lower part 11 a of the vehicle body frame 11 of the vehicle body3. The right front wheel 4R is rotatably provided via a right supportpart 30R at a distal end (front part) of the right front wheel arm 12R.

The right front wheel arm 12R is swingable about a right swing shaft21R. The right swing shaft 21R is provided to extend in the left-rightdirection. The left front wheel arm 12L is supported on the front lowerpart 11 a of the vehicle body frame 11, similarly to the right frontwheel arm 12R. The left front wheel arm 12L is swingable about a leftswing shaft 21L. The right swing shaft 21R is arranged coaxially withthe left swing shaft 21L.

In a side view, the right front wheel arm 12R is formed in a lateralsubstantially Y-shape open the front side. The right front wheel arm 12Rincludes a swing support part 25, a first protrusion part 26, and asecond protrusion part 27.

The swing support part 25 is provided on a rear part of the right frontwheel arm 12R. The swing support part 25 constitutes the base end of theright front wheel arm 12R. In a plan view, the swing support part 25 isbent so that the right front wheel arm 12 is inside in the vehicle widthdirection as it approach the front side. The right swing shaft 21R isarranged at a rear end of the swing support part 25.

The first protrusion part 26 is provided so as to protrude forward fromthe upper side of a front end of the swing support part 25. A front endof the first protrusion part 26 is positioned inside the right frontwheel 4R in the vehicle width direction.

The second protrusion part 27 is provided so as to protrude forward fromthe lower side of the front end of the swing support part 25. A frontend of the second protrusion part 27 is positioned inside the rightfront wheel 4R in the vehicle width direction.

The first protrusion part 26 and the second protrusion part 27 arearranged side by side in the up-down direction. The right support part30R is attached to the front end of the first protrusion part 26 and thefront end of the second protrusion part 27 so as to straddle them.

The right support part 30R is provided at a front end of the right frontwheel arm 12R so as to be rotatable about a right steering shaft 31R.The right support part 30R is arranged inside in the vehicle widthdirection with respect to a middle portion of the right front wheel 4R.The right steering shaft 31R is provided so as to extend substantiallyin the up-down direction. The right steering shaft 31R is inclined sothat an upper end thereof is positioned rearward than a lower end.

The right front wheel 4R is attached to the right support part 30R. Theright front wheel 4R is rotatable about an axle 80 extending in theleft-right direction with respect to the right support part 30R. A righthandle stem (right extension) 35R included in the steering handle 17 isattached to the right support part 30R. The right support part 30Rrotates about the right steering shaft 31R together with the righthandle stem 35R.

The steering handle 17 includes a right handle grip (right steeringoperation part) 36R corresponding to the right handle stem 35R. When thedriver operates by gripping the right handle grip 36R, the right supportpart 30R rotates via the right handle stem 35R. As a result, anorientation of the right front wheel 4R can be changed.

The right handle stem 35R extends obliquely rearward and upward from theright support part 30R (in a direction away from the right front wheel4R). A base end (lower end) of the right handle stem 35R is fixed to theright support part 30R. The base end of the right handle stem 35R isarranged inside in the vehicle width direction with respect to the rightfront wheel 4R.

The right handle grip 36R is provided at an upper part of the righthandle stem 35R, as shown in FIG. 5. The right handle grip 36R isarranged so as to protrude outward in the vehicle width direction fromthe right handle stem 35R.

In connection with the left front wheel 4L, the steering handle 17includes a left handle stem (left extension) 35L and a left handle grip(left steering operation part) 36L. The left and right handle stems 35L,35R are spaced from each other in the left-right direction.

The left and right handle stems 35L, 35R are respectively connected tothe left and right front wheels 4 from the inside in the vehicle widthdirection. Therefore, regardless of a position of the steering handle 17with respect to the driver, a distance between the left front wheel 4Land the right front wheel 4R can be easily increased. That is, thepositions of the left front wheel 4L and the right front wheel 4R arenot restricted by the steering handle 17, and a width between the bothwheels 4L and 4R be easily adjusted.

The right handle stem 35R and the left handle stem 35L are coupled viaan interlocking link mechanism 40. When one of the left support part 30Land right support part 30R is rotated for steering, the interlockinglink mechanism 40 can rotate the opposite in conjunction therewith.

Next, the interlocking link mechanism 40 will be described withreference to FIGS. 2 to 7. FIG. 6 is a front perspective view showing astate in which the left and right front wheels 4 are turned for steeringfrom the neutral state to the left in FIG. 2. FIG. 7 is a view showing alean state of the vehicle body 3.

The interlocking link mechanism 40 includes an interlocking arm(rotation base portion) 50, a first left coupling portion 51, a secondleft coupling portion 52, a left rod 53, a first right coupling portion56, a second right coupling portion 57, and a right rod 58.

As shown in FIG. 2, the interlocking arm 50 is formed so as to extendlinearly. The interlocking arm 50 is arranged between the left frontwheel 4L and the right front wheel 4R in a front view. The interlockingarm 50 is arranged so that its longitudinal direction is along theleft-right direction in the steering neutral state. A middle part in thelongitudinal direction of the interlocking arm 50 is supported on thevehicle body 3 so as to be rotatable about a first rotary shaft 66.

The first rotary shaft 66 is arranged so as to extend in the up-downdirection. The first rotary shaft 66 is arranged at the center of thetraveling vehicle 1 in the left-right direction.

In this embodiment, the interlocking arm 50 is composed of a flatplate-like member. The interlocking arm 50 is provided with a first bossportion 61, a second boss portion 62, and a third boss portion 63. Eachof the first boss portion 61, the second boss portion 62, and the thirdboss portion 63 is formed in a cylindrical shape. The axes of the firstboss portion 61, the second boss portion 62, and the third boss portion63 are respectively oriented in the up-down direction.

The first boss portion 61 is arranged at the center in the longitudinaldirection of the interlocking arm 50. The first rotary shaft 66 isinserted into the first boss portion 61. The first boss portion 61 issupported by the front lower part 11 a of vehicle body frame 11 invehicle body 3 so that the interlocking arm 50 can rotate about thefirst rotary shaft 66.

The second boss portion 62 is provided at one end in the longitudinaldirection of the interlocking arm 50. The second boss portion 62 isarranged on a left side of the first boss portion 61. A second rotaryshaft 67 is inserted into the second boss portion 62, and is rotatablysupported by the second boss portion 62. The second rotary shaft 67 isarranged so as to extend in the up-down direction.

The third boss portion 63 is provided at the other end in thelongitudinal direction of the interlocking arm 50. The third bossportion 63 is arranged on a right side of the first boss portion 61. Athird rotary shaft 68 is inserted into the third boss portion 63, and isrotatably supported by the third boss portion 63. The third rotary shaft68 is arranged so as to extend in the up-down.

The first left coupling portion 51 is a U-shaped member. The first leftcoupling portion 51 is fixed to an upper end of the second rotary shaft67 so that the upper side of the first left coupling portion 51 isopened. The first left coupling portion 51 is rotatable with the secondrotary shaft 67. When the interlocking arm 50 rotates about the firstrotary shaft 66, the first left coupling portion 51 moves with a leftpart of the interlocking arm 50.

The second left coupling portion 52 is arranged in front of the firstleft coupling portion 51. The second left coupling portion 52 is aU-shaped member, and is attached to the left handle stem 35L so that theinner side of the second left coupling portion 52 in the vehicle widthdirection is opened. The second left coupling portion 52 is fixed to anend of a third rotary shaft 81 extending in the left-right direction.The third rotary shaft 81 is rotatably supported by a base end of theleft handle stem 35L.

The left rod 53 couples the first left coupling portion 51 and thesecond left coupling portion 52 so that the interlocking arm 50 and theleft support part 30L interlock with each other. The left rod 53 isprovided so as to extend in a front-back direction. The left rod 53extends linearly between the first left coupling portion 51 and thesecond left coupling portion 52. The left rod 53 is arranged so as topass through a space formed between the first protrusion part 26 and thesecond protrusion part 27 of the left front wheel arm 12L in thefront-back direction

One end (rear part) in the longitudinal direction of left rod 53 iscoupled to the first left coupling portion 51 so as to be rotatableabout a first coupling shaft 71. The first coupling shaft 71 is arrangedso as to extend in the left-right direction (direction perpendicular tothe up-down direction). The first coupling shaft 71 is arrangedcoaxially with left swing shaft 21L of the left front wheel arm 12L inthe steering neutral state.

The other end (front part) in the longitudinal direction of left rod 53is coupled to the second left coupling portion 52 so as to be rotatableabout a second coupling shaft 72. The second coupling shaft 72 isarranged so as to extend in the up-down direction.

The first right coupling portion 56 is a U-shaped member. The firstright coupling portion 56 is fixed to an upper end of the third rotaryshaft 68 so that the upper side of the first right coupling portion 56is opened. The first right coupling portion 56 is rotatable with thethird rotary shaft 68. When the interlocking arm 50 rotates about thefirst rotary shaft 66, the first right coupling portion 56 moves withthe right part of the interlocking arm 50.

The second right coupling portion 57 is arranged in front of the firstright coupling portion 56. The second right coupling portion 57 is aU-shaped member, and is attached to the right handle stem 35R so thatthe inner side of the second right coupling portion 57 in the vehiclewidth direction is opened. The second right coupling portion 57 is fixedto an end of a fourth rotary shaft 82 extending in the left-rightdirection. The fourth rotary shaft 82 is rotatably supported by the baseend of the right handle stem 35R.

The right rod 58 couples the first right coupling portion 56 and thesecond right coupling portion 57 so that the interlocking arm 50 and theright support part 30R interlock with each other. The right rod 58 isprovided so as to extend in the front-back direction. The right rod 58extends linearly between the first right coupling portion 56 and thesecond right coupling portion 57. The right rod 58 is arranged so as topass through a space formed between the first protrusion 26 and thesecond protrusion 27 of the right front wheel arm 12R in the front-backdirection

One end (rear part) in the longitudinal direction of the right rod 58 iscoupled to the first right coupling portion 56 so as to be rotatableabout a third coupling shaft 73. The third coupling shaft 73 is arrangedso as to extend in the left-right direction (direction perpendicular tothe up-down direction). The third coupling shaft 73 is arrangedcoaxially with right swing shaft 21R of the right front wheel arm 12R inthe steering neutral state.

The other end (front part) in the longitudinal direction of the rightrod 58 is coupled to the second right coupling portion 57 so as to berotatable about a fourth coupling shaft 74. The fourth coupling shaft 74is arranged so as to extend in the up-down direction.

With the interlocking link mechanism 40 configured as described above,in conjunction with rotating one of the left support part 30L and rightsupport part 30R by steering handle 17, it is possible to rotate theother. For example, in the steering neutral state shown in FIG. 2,consider a case where the driver operates the right steering wheel 17 torotate the right support part 30R for steering to the left. In thiscase, the right rod 58 is moved rearward in response to the rotation ofthe right handle stem 35R, and the interlocking arm 50 rotates clockwiseabout the first rotary shaft 66 in plan view. As a result, the left rod53 moves forward, and the left support part 30L can be rotated togetherwith the left handle stem 35L. Therefore, the steering angle of theright front wheel 4R and the steering angle of the left front wheel 4Lcan be changed in cooperation with each other, and the operabilityregarding steering is good.

Next, the lean of vehicle body 3 will be described. In the state shownin FIG. 5, the traveling vehicle 1 can tilt the vehicle body 3 in theleft-right direction by raising one of the left and right front wheelarms 12 and lowering the other. At this time, the suspension device 20functions as a kind of link mechanism, and when one of the left andright front wheel arm 12 rises, the other is lowered. FIG. 7 shows astate in which the heights of the left and right front wheels 4 aredifferent. In order to facilitate comparison with FIG. 5, the vehiclebody 3 is drawn upright in FIG. 7, but in reality, the vehicle body 3leans according to the difference in height between the left and rightfront wheels 4 shown in FIG. 7.

In the steering neutral state, the first coupling shaft 71 and the thirdcoupling shaft 73 are substantially oriented in the left-rightdirection. Similarly, the third and fourth rotary shafts 81, 82 are alsooriented substantially in the left-right direction. Thus, the left rod53 of the interlocking link mechanism 40 swings according to the swingof the left front wheel arm 12L, and the right rod 58 swings accordingto the swing of the right front wheel arm 12R. Therefore, regardless ofthe lean/non-lean state of the vehicle body 3, the steering angle of theleft and right front wheel 4 can be changed in conjunction with eachother with the interlocking link mechanism 40. Further, in thisembodiment, at the time of steering neutral, left swing shaft 21L, thefirst coupling shaft 71, the third coupling shaft 73 and right swingshaft 21R are all arranged coaxially. Therefore, even when vehicle body3 is lean, the left and right front wheels 4 can be smoothly interlockedby efficiently transmitting the force between the left support part 30Land the right support part 30R.

As above, the right front wheel arm 12R is formed laterally in asubstantially Y shape, and the right support part 30R is attached to thefront ends of the right front wheel arm 12R which is branched into twoso as to straddle the front ends. Therefore, a structure having highmechanical strength can be obtained by combining the right front wheelarm 12R and the right support part 30R. As a result, the right frontwheel 4R can be reliably supported. Further, since the right rod 58passes between the two branched parts of the right front wheel arm 12R,a compact structure can be realized as a whole. The same applies to theleft front wheel arm 12L.

As described above, the traveling vehicle 1 of this embodiment includesthe vehicle body 3, the left front wheel arm 12L, the right front wheelarm 12R, the left support part 30L, the left front wheel 4L, the rightsupport part 30R, the right front wheel 4R, and the interlocking linkmechanism 40. The left front wheel arm 12L is arranged on one side inthe vehicle width direction, is provided so as to extend forward fromthe vehicle body 3, and is supported on the vehicle body 3 so as to beswingable in an up-down direction. The right front wheel arm 12R isarranged on the other side in the vehicle width direction, is providedso as to extend forward from the vehicle body 3, and is supported on thevehicle body 3 so as to be swingable in an up-down direction. The leftsupport part 30L is provided on a front part of the left front wheel arm12L so as to be rotatable about the left steering shaft 31L. The leftfront wheel 4L is rotatably supported by the left support part 30L andis configured to change an orientation of the left front wheel 4L byrotation of the left support part 30L about the left steering shaft 31L.The right support part 30R is provided on a front part of the rightfront wheel arm 12R so as to be rotatable about the right steering shaft31R. The front right wheel 4R is rotatably supported by the rightsupport part 30R and is configured to change the orientation of thefront right wheel 4R by rotation of the right support part 30R about theright steering shaft 31R. The interlocking link mechanism 40 isconfigured to rotate one of the left support part 30L and the rightsupport part 30R in conjunction with the other when the other of theleft support part 30L and the right support part 30R rotates. Theinterlocking link mechanism 40 is provided between the left support part30L and the right support part 30R.

Thus, in the traveling vehicle 1 including the left front wheel 4L andthe right front wheel 4R, it is possible to realize that the vehiclebody 3 leans. Further, based on the rotation of one of the left supportpart 30L and the right support part 30R, the rotation state of the otherof the left support part 30L and the right support part 30R can bechanged. That is, based on the steering angle of one of the left frontwheel 4L and the right front wheel 4R corresponding to the one of theleft support part 30L and the right support part 30R, the steering angleof the other of the left front wheel 4L and the right front wheel 4Rcorresponding to the other of the left support part 30L and the rightsupport part 30R can be changed. Therefore, with respect to the steeringof the traveling vehicle 1, good operability can be realized.

In the traveling vehicle 1 of this embodiment, the interlocking linkmechanism 40 includes the interlocking arm 50, the first left couplingportion 51, the second left coupling portion 52, the left rod 53, thefirst right coupling portion 56, the second right coupling portion 57,and the right rod 58. The interlocking arm 50 is supported on thevehicle body 3 at the center of the vehicle body 3 in the vehicle widthdirection so as to be rotatable about a first rotary shaft extending inthe up-down direction. The first left coupling portion 51 is provided onthe left part of the interlocking arm 50 so as to be rotatable about thesecond rotary shaft 67 extending in the up-down direction. The secondleft coupling portion 52 is rotatable integrally with the left supportpart 30L about the left steering shaft 31L. The left rod 53 extends inthe front-back direction and couples the first left coupling portion 51and the second left coupling portion 52 so that the interlocking arm 50and the left support part 30L are interlocked with each other. The firstright coupling portion 56 is provided on the right part of theinterlocking arm 50 so as to be rotatable about the third rotary shaft68 extending in the up-down direction. The second right coupling portion57 is rotatable integrally with the right support part 30R about theright steering shaft 31R. The right rod 58 extends in the front-backdirection and couples the first right coupling portion 56 and the secondright coupling portion 57 so that the interlocking arm 50 and the rightsupport part 30R are interlocked with each other.

Thus, the interlocking link mechanism 40 can be simply configured forthe left front wheel 4L and the right front wheel 4R.

In the traveling vehicle 1 of this embodiment, the first rotary shaft 66is arranged at the center of the vehicle body 3 in the vehicle widthdirection.

Thus, the interlocking link mechanism 40 can be operated satisfactorily.Further, it is easy to change the orientations of the two front wheels 4symmetrically during left and right steering.

In the traveling vehicle 1 of this embodiment, the rear part of the leftrod 53 is coupled to the first left coupling portion 51 so as to berotatable about a first coupling shaft 71 extending in a directionperpendicular to the up-down direction. The front part of the left rod53 is coupled to the second left coupling portion 52 so as to berotatable about a second coupling shaft 72 extending in the up-downdirection. The rear part of the right rod 58 is coupled to the firstright coupling portion 56 so as to be rotatable about a third couplingshaft 73 extending in a direction perpendicular to the up-downdirection. The front part of the right rod 58 is coupled to the secondright coupling portion 57 so as to be rotatable about a fourth couplingshaft 74 extending in the up-down direction.

Thus, the interlocking link mechanism 40 using the left rod 53 and theright rod 58 can be smoothly operated.

In the traveling vehicle 1 of this embodiment, the left front wheel arm12L is supported on the vehicle body 3 about left swing shaft 21Lextending in the vehicle width direction. The left swing shaft 21L isarranged coaxially with the first coupling shaft 71 in the steeringneutral state. The right front wheel arm 12R is supported on the vehiclebody 3 about a right swing shaft 21R extending in the vehicle widthdirection. The right swing shaft 21R is arranged coaxially with thethird coupling shaft 73 in the steering neutral state.

Thus, the interlocking link mechanism 40 can be smoothly operated evenwhen the vehicle body 3 is lean.

Further, traveling vehicle 1 of this embodiment includes the handle stem35L, the handle grip 36L, the handle stem 35R, and the handle grip 36R.The handle stem 35L extends in the direction away from the left supportpart 30L with respect to the left front wheel 4L. The handle grip 36L isprovided on the handle stem 35L and can be gripped by the driver. Thehandle stem 35 R extends in the direction away from the right supportpart 30R with respect to the right front wheel 4R. The handle grip 36Ris provided on the handle stem 35R and can be gripped by the driver.

Thus, the steering operation using at least one of the left handle grip36L and the right handle grip 36R can directly change the orientation ofthe left front wheel 4L and the right front wheel 4R. Therefore, whenchanging the orientation of the left front wheel 4L and right frontwheel 4R, a good operation feeling can be realized.

In the traveling vehicle 1 of this embodiment, each of the left frontwheel arm 12L and right front wheel arm 12R includes the swing supportpart 25, a first protrusion part 26, and a second protrusion part 27.The swing support part 25 is supported on vehicle body 3 so as to beswingable. The first protrusion part 26 protrudes forward from the swingsupport part 25. The second protrusion part 27 is arranged below thefirst protrusion part 26 and protrudes forward from the swing supportpart 25. The left support part 30L is attached to the first protrusionpart 26 and the second protrusion 27 of the left front wheel arm 12L.The right support part 30R is attached to the first protrusion part 26and the second protrusion 27 of the right front wheel arm 12R.

Thus, another component (for example, the left rod 53 or the right rod58, which is a component of the interlocking link mechanism 40) can bearranged between the first protrusion part 26 and the second protrusionpart 27. Therefore, a compact structure can be realized as a whole.Further, sufficient strength can be secured for each of the left frontwheel arm 12L and the right front wheel arm 12R.

Although a preferred embodiment of the present invention has beendescribed above, the configuration described above can be modified, forexample, as follows.

The left support part 30L may be integrally formed with the left handlestem 35L. The right support part 30R may be integrally formed with theright handle stem 35R.

The interlocking arm 50 is not limited to a linear arm, but may beconfigured as a V-shaped arm, for example.

The left rod 53 and the right rod 58 may be arranged parallel to eachother in a plan view at the steering neutral state, or may be arrangednot to be parallel to each other.

The interlocking link mechanism 40 is not limited to being applied to asaddle-ride type vehicle, but can be applied to other types of travelingvehicles as long as each of them has the left and right front wheels 4.

A steering handle attached to the interlocking arm 50 of theinterlocking link mechanism 40 may be adopted. In this case, thesteering handle includes a steering shaft (extension) extending upwardfrom the interlocking arm 50 (in a direction away from the interlockingarm 50), and a handle grip (steering operation) which is provided on thesteering shaft and which can be gripped by the driver.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

What is claimed is:
 1. A traveling vehicle, comprising: a vehicle body;a left swing part which is arranged on one side in a vehicle widthdirection, which is provided so as to extend forward from the vehiclebody, and which is supported on the vehicle body so as to be swingablein an up-down direction; a right swing part which is arranged on theother side in the vehicle width direction, which is provided so as toextend forward from the vehicle body, and which is supported on thevehicle body so as to be swingable in the up-down direction; a leftsupport part which is provided on a front part of the left swing part soas to be rotatable about a left steering shaft; a left front wheel whichis rotatably supported by the left support part and which is configuredto change an orientation of the left front wheel by rotation of the leftsupport part about the left steering shaft, a right support part whichis provided at a front part of the right swing part so as to berotatable about a right steering shaft; a right front wheel which isrotatably supported by the right support part and which is configured tochange an orientation of the right front wheel by rotation of the rightsupport part about the right steering shaft; a steering operation partto be gripped by a driver which is swingable in the up-down directionalong with the left and right front wheels; and an interlocking linkmechanism which is configured to rotate one of the left support part andthe right support part in conjunction with the other when the other ofthe left support part and the right support part rotates, wherein theinterlocking link mechanism is provided between the left support partand the right support part.
 2. The traveling vehicle according to claim1, wherein the interlocking link mechanism includes: a rotation baseportion which is supported on the vehicle body at a center of thevehicle body in the vehicle width direction so as to be rotatable abouta first rotary shaft extending in the up-down direction; a first leftcoupling portion which is provided on a left part of the rotation baseportion so as to be rotatable about a second rotary shaft extending inthe up-down direction; a second left coupling portion which is rotatableintegrally with the left support part about the left steering shaft; aleft rod that extends in a front-back direction and couples the firstleft coupling portion and the second left coupling portion so that therotation base portion and the left support part are interlocked witheach other; a first right coupling portion which is provided on a rightpart of the rotation base portion so as to be rotatable about a thirdrotary shaft extending in the up-down direction; a second right couplingportion which is rotatable integrally with the right support part aboutthe right steering shaft; and a right rod that extends in the front-backdirection and couples the first right coupling portion and the secondright coupling portion so that the rotation base portion and the rightsupport part are interlocked with each other.
 3. The traveling vehicleaccording to claim 2, wherein the first rotary shaft is arranged at thecenter of the vehicle body in the vehicle width direction.
 4. Thetraveling vehicle according to claim 2, wherein a rear part of the leftrod is coupled to the first left coupling portion so as to be rotatableabout a first coupling shaft extending in a direction perpendicular tothe up-down direction, wherein a front part of the left rod is coupledto the second left coupling portion so as to be rotatable about a secondcoupling shaft extending in the up-down direction, wherein a rear partof the right rod is coupled to the first right coupling portion so as tobe rotatable about a third coupling shaft extending in the directionperpendicular to the up-down direction, and wherein a front part of theright rod is coupled to the second right coupling portion so as to berotatable about a fourth coupling shaft extending in the up-downdirection.
 5. The traveling vehicle according to claim 4, wherein theleft swing part is supported on the vehicle body about a left swingshaft extending in the vehicle width direction, wherein the left swingshaft is arranged coaxially with the first coupling shaft in in asteering neutral state, wherein the right swing part is supported on thevehicle body about a right swing shaft extending in the vehicle widthdirection, and wherein the right swing shaft is arranged coaxially withthe third coupling shaft in the steering neutral state.
 6. The travelingvehicle according to claim 2, further comprising: an extension extendingin a direction away from the rotation base portion, wherein the steeringoperation part is provided on the extension.
 7. The traveling vehicleaccording to claim 1, further comprising: a left extension extending ina direction away from the left support part with respect to the leftfront wheel; a left steering operation portion of the steering operationpart is provided on the left extension and which can be gripped by thedriver; a right extension extending in a direction away from the rightsupport part with respect to the right front wheel; and a right steeringoperation portion of the steering operation part is provided on theright extension and which can be gripped by the driver.
 8. The travelingvehicle according to claim 1, wherein each of the left swing part andthe right swing part includes: a swing support part supported on thevehicle body so as to be swingable; a first protrusion part protrudingforward from the swing support part; and a second protrusion part whichis arranged below the first protrusion part and which protrudes forwardfrom the swing support part, wherein the left support part is attachedto the first protrusion part and the second protrusion of the left swingpart, and wherein the right support part is attached to the firstprotrusion part and the second protrusion part of the right swing part.9. The traveling vehicle according to claim 1, wherein the steeringoperation part swings in the up-down direction when the left swing partor the right swing part swings.
 10. The traveling vehicle according toclaim 1, wherein the interlocking link mechanism comprises: a left rodwhich is swingable about a shaft arranged coaxially with a shaft whichthe left swing part swings; and a right rod which is swingable about ashaft arranged coaxially with a shaft which the right swing part swings.11. The traveling vehicle according to claim 10, wherein the left rod islocated between an upper side and a lower side of the left swing partand the right rod is located between an upper side and a lower side ofthe right swing part.
 12. The traveling vehicle according to claim 1,where each of the left swing part and the right swing part includes: aswing support part supported on the vehicle body so as to be swingable;a first protrusion part protruding forward from the swing support part;and a second protrusion part protruding forward from the swing supportpart.
 13. The traveling vehicle according to claim 12, wherein the firstprotrusion part and the second protrusion part are branched from theswing support part.
 14. The traveling vehicle according to claim 12,further comprises: a left extension extending in a direction away fromthe left support part with respect to the left front wheel; a leftsteering operation portion of the steering operation part is provided onthe left extension and which can be gripped by the driver; a rightextension extending in a direction away from the right support part withrespect to the right front wheel; and a right steering operation portionof the steering operation part is provided on the right extension andwhich can be gripped by the driver.
 15. The traveling vehicle accordingto claim 14, wherein the left steering operation part swingsindependently from the right steering operation part when the left swingpart swings.
 16. The traveling vehicle according to claim 14, whereinthe right steering operation part swings independently from the leftsteering operation part when the right swing part swings.
 17. Thetraveling vehicle according to claim 1, wherein the steering operationpart is gripped by one hand of the driver.
 18. A traveling vehicle,comprising: a vehicle body; a left swing part which is arranged on oneside in a vehicle width direction, which is provided so as to extendforward from the vehicle body, and which is supported on the vehiclebody so as to be swingable in an up-down direction; a right swing partwhich is arranged on the other side in the vehicle width direction,which is provided so as to extend forward from the vehicle body, andwhich is supported on the vehicle body so as to be swingable in theup-down direction; a left support part which is provided on a front partof the left swing part so as to be rotatable about a left steeringshaft; a left front wheel which is rotatably supported by the leftsupport part and which is configured to change an orientation of theleft front wheel by rotation of the left support part about the leftsteering shaft, a right support part which is provided at a front partof the right swing part so as to be rotatable about a right steeringshaft; a right front wheel which is rotatably supported by the rightsupport part and which is configured to change an orientation of theright front wheel by rotation of the right support part about the rightsteering shaft; an interlocking link mechanism which is configured torotate one of the left support part and the right support part inconjunction with the other when the other of the left support part andthe right support part rotates, wherein the interlocking link mechanismis provided between the left support part and the right support part,wherein the interlocking link mechanism includes: a rotation baseportion which is supported on the vehicle body at a center of thevehicle body in the vehicle width direction so as to be rotatable abouta first rotary shaft extending in the up-down direction; a first leftcoupling portion which is provided on a left part of the rotation baseportion so as to be rotatable about a second rotary shaft extending inthe up-down direction; a second left coupling portion which is rotatableintegrally with the left support part about the left steering shaft; aleft rod that extends in a front-back direction and couples the firstleft coupling portion and the second left coupling portion so that therotation base portion and the left support part are interlocked witheach other; a first right coupling portion which is provided on a rightpart of the rotation base portion so as to be rotatable about a thirdrotary shaft extending in the up-down direction; a second right couplingportion which is rotatable integrally with the right support part aboutthe right steering shaft; and a right rod that extends in the front-backdirection and couples the first right coupling portion and the secondright coupling portion so that the rotation base portion and the rightsupport part are interlocked with each other, wherein a rear part of theleft rod is coupled to the first left coupling portion so as to berotatable about a first coupling shaft extending in a directionperpendicular to the up-down direction, wherein a front part of the leftrod is coupled to the second left coupling portion so as to be rotatableabout a second coupling shaft extending in the up-down direction,wherein a rear part of the right rod is coupled to the first rightcoupling portion so as to be rotatable about a third coupling shaftextending in the direction perpendicular to the up-down direction, andwherein a front part of the right rod is coupled to the second rightcoupling portion so as to be rotatable about a fourth coupling shaftextending in the up-down direction; and wherein the left swing part issupported on the vehicle body about a left swing shaft extending in thevehicle width direction, wherein the left swing shaft is arrangedcoaxially with the first coupling shaft in in a steering neutral state,wherein the right swing part is supported on the vehicle body about aright swing shaft extending in the vehicle width direction, and whereinthe right swing shaft is arranged coaxially with the third couplingshaft in the steering neutral state.